We propose to identify functional interactions between Ago-miRNA and neuron-specific RNA binding proteins (nRNABPs) in the normal and stressed mouse brain. RNA regulation in vivo involves the superimposed and likely combinatorial action of many RNABPs, but most investigations of RNABPs have focused on the role of individual proteins in vitro. This has confined our understanding of conventional regulation by RNABPs and how they intersect with Argonaute (Ago) mediated miRNA regulation; while it is suspected that these two systems intersect, there is almost no understanding of where they do so or what the functional consequences are. The expanding list of RNABPs and miRNAs associated with neurologic disease has underscored large gaps in our understanding of their roles in disease pathogenesis. We developed HITS-CLIP during the last funding period, a revolutionary approach to the study of protein-RNA regulation, and will apply it for the first time to studying coordinate and dynamic regulation by Ago-miRNA and neuronal RNABPs. These studies will be applied to normal brain, using homologous recombination in mice to establish robust and relevant in vivo study in neurons. They will then be applied to stress brain, using three brain-disease relevant paradigms.